lit-ui-router-ssr / vite
vite
The Vite plugin for a Lit app: ui-router-server/vite's serverRouterPlugin, with the prerender worker set up for Lit. It names a DOM shim (@lit-labs/ssr's by default) and lit-ui-router-ssr/register as preloads, so the prerender script imports the app, the router and this package statically, and definePrerender calls this package's prerender() with the options the script returns.
Nothing here imports Lit, @lit-labs/ssr or Vite, so vite.config.ts loads it without defining an element or installing a global in Vite's process.